One of the Bank of England’s nine rate-setters has raised questions about the effectiveness of its forward guidance economic rescue policy, putting him at odds with the Bank’s Governor.

Martin Weale calculated that the Bank’s pledge not to raise interest rates until unemployment drops to 7 per cent would, at best, raise growth by 0.75 per cent over two years. However, he said he doubted that the impact would be so large because households and businesses did not fully understand the policy.

His comments, which he emphasised did not reflect the Bank’s thinking, will be a blow to Mark Carney,